[ND40oz]

I did the 1200 mile oil and gearbox change in my 135i. The only reason I didn't do the diff was because I was planning on replacing it with a bolted auto unit with an LSD. Any manual vehicle I do the gearbox oil at 1200 miles along with engine oil.

Here's a good read from one guy doing all three on his 1200 mile 128i: http://www.1addicts.com/forums/showthread.php?t=409293

[catskillclimber]

oil analysis is the only way to determine optimum intervals "your" vehicle if longevity is your goal. I did the 1200 mile engine oil change in our 328D and found the viscosity had already decreased from the factory SAE 30 to SAE 20. SAE 20 is outside any recommended viscosity range and BMW will not confirm how low the viscosity can go without detrimental effects. I opted for the 2nd change around 6,500 miles later and found the similar viscosity decrease. This continued in the 15,000 mile sample but did not occur in the 20,000 mile sample. Iron wear rates declined over the same period and appear to be leveling off with the 20,000 sample. I suspect I'll be able to stretch intervals out to 8-10k miles at this point.

I also changed front & rear differential fluid at ~3,000 miles. I didn't have the oil analyzed but did save samples. Each diff had produced an ~4mm deep layer of fine metal particles. The front diff was also darker in color, not sure if this is from fine dirt particles or the diff were filled from different sources. See pic.

ZF recommends 50k intervals on their transmissions which is 1/2 the BMW interval.

[Thumper333]

Originally Posted by ND40oz

Here's a good read from one guy doing all three on his 1200 mile 128i: http://www.1addicts.com/forums/showthread.php?t=409293

Very good stuff.

Pretty conclusive findings there.


I almost feel bad not doing my normal process with my current cars, BUT.....since they are leases and it's unlikely I will keep them past lease term I sort of feel like it's their car, and if they don't feel like servicing it for longevity, than why should I?

[Thumper333]

Originally Posted by murrays

Simple logical answer, if the life of the oil is, say, 10k miles, starting with "broken in" oil would shorten the useful life. I have no idea if oil gets better or not since I've never looked into it.

Your answer doesn't address the question. Your "answer" actually supports my point. If that was your purpose, great. Used oil has a shortened service life than new and has more contaminants in it, therefore used oil is never "better" than new oil.

Originally Posted by murrays

Yes, I base my statements from my experience working as a design engineer for Cummins Filtration for 10 years. What qualifications do you bring to the table?

Those particles that get trapped, as you mention, allow the filter to trap smaller particles that would pass through a new filter. That's what I mean by "better".

I have been an ASE and I-CAR certified technician and appraiser for, oh, about 21 years. I deal in the real world with things engineers design in labs.

So you design your filters with BIG holes, and then hope that a BIG particle gets trapped there so that it can then trap smaller particles? So until enough big particles come by all the small ones are moving through and causing damage? That sounds like a great design. Why not just design the filter to trap the smallest possible particles before introducing enough resistance to cause flow issues? Since once those "big" particles block up the place you'll have the same flow issues anyway. And once that flow pressure builds up it will break those big pieces loose, making bigger holes, needing bigger pieces.

Dear god man, if you were designing bridges would you just use the carcasses of all the cars that crashed into the river for the supports? LOL

Originally Posted by stormlv

You do know what an analogy is, right?
It's like saying a pump and a heart don't make for a good analogy because one is biological and works with blood and the other is man made, electrical and works with water.

I am very familiar with an analogy. See what I did above was sort of an analogy but with some hyperbole mixed in for fun.

Your heart and pump analogy is a great one, since both devices pump fluid in EXACTLY the same manner for exactly the same purpose. Unless you use wine to lubricate moving parts.....your wine/oil analogy is flawed, and as I said before, completely pointless.

Originally Posted by stormlv

Look, what I was trying to say is that you are making an assumption when you say that any use of an oil degrades the quality of it.

That is not an assumption, that is a fact. YOU are making an assumption based on feelings that adding dirt and compressing an oil does NOT degrade it.

LOL

I mean seriously man, if use of an oil does NOT degrade it........why do we ever change it?

[murrays]

Originally Posted by Thumper333

I have been an ASE and I-CAR certified technician and appraiser for, oh, about 21 years. I deal in the real world with things engineers design in labs.

So you design your filters with BIG holes, and then hope that a BIG particle gets trapped there so that it can then trap smaller particles? So until enough big particles come by all the small ones are moving through and causing damage? That sounds like a great design. Why not just design the filter to trap the smallest possible particles before introducing enough resistance to cause flow issues? Since once those "big" particles block up the place you'll have the same flow issues anyway. And once that flow pressure builds up it will break those big pieces loose, making bigger holes, needing bigger pieces.

Dear god man, if you were designing bridges would you just use the carcasses of all the cars that crashed into the river for the supports? LOL

So how many filter efficiency vs. life tests have you conducted? I'll assume none based on your condescending tone.

It's not so much that filters are designed that way, it's a fact of how filter work in the "real world". Read this and you might learn something they didn't teach in your technician school: http://www.pureairsystems.com/Pure-A...-Filtrat1.html

Mechanical air filters operate on two filtration principals, primary air filtration or impingement of the dust on the media itself, and secondary air filtration which is the dust or filter cake on the filter removing or filtering out smaller dust particles. Figure A1 shows the air filter when it is first installed. Most of the air filtration takes place in the media itself. Figure A2 shows the air filter with dust on the media and the particle reduction efficiency gets better as the filter loads up. All mechanical air filters operate in this manner.

Here's another link for you to read with a nice chart: http://multimedia.3m.com/mws/media/6...ting-value.pdf

And to answer your same question for the third or forth time, if you designed the filter for maximum particle reduction efficiency when new, you'd be changing it several times a year due to the high air restriction.

[Thumper333]

Originally Posted by murrays

So how many filter efficiency vs. life tests have you conducted? I'll assume none based on your condescending tone.

It's not so much that filters are designed that way, it's a fact of how filter work in the "real world". Read this and you might learn something they didn't teach in your technician school: http://www.pureairsystems.com/Pure-A...-Filtrat1.html

LMAO If I was being condescending (I wasn't FYI) what would you call that little hissy fit of yours? Nope, you are right, in my "technician school" for repairing automobiles HEPA air filtration systems for homes were never taught.

Now, I am going to ask and this is NOT to be condescending but I am not sure if there is a greater mis-understanding here or if you just are not reading the posts.

We are talking about OIL filters. I have no idea how any of the technical data regarding HVAC, HEPA, or gas phase absorption filters applies in any way shape or form. While one could argue the basic theories are similar, the systems they service and more specific operating environments are so vastly different as to make any comparison vague and generic only. But if we use that logic, than I am expertly qualified on HEPA air systems based on my training with oil filters. It's all the same.

Originally Posted by murrays

And to answer your same question for the third or forth time,

Trying to see where you answered a question even once, let alone multiple times. You came in with a wild statement to which I asked for the basis of it, meaning technical data directly related to the statement and I got a snooty, condescending response about your career qualifications. Then in a classic fallacy based argument a request for proof/data was answered with a demand for a list of qualifications to even QUESTION your statement. Now after offering qualifications to even participate in the discussion the attack moves to claiming offense where there clearly was none to manipulate the conversation into sympathy based acceptance.

Originally Posted by murrays

if you designed the filter for maximum particle reduction efficiency when new, you'd be changing it several times a year due to the high air restriction.

Again, since we are talking about OIL filters I don't really care about air restriction. The fact that a filter increases restriction over it's life A) means it's working and B) is why we change them. If I had to change the filter "several times a year" as you toss out to attempt acceptance from fear, but the result was a cleaner, longer lasting engine I would certainly have no problem with it. Luckily with normal driving it requires only 2 changes a year, certainly nothing so strenuous or time consuming. The purpose of a filter is to filter, designing it with a flaw in it's primary function for a measure of convenience is fairly bad planning.

I have no dog in this fight, I could care less how you or anyone else cares for their property. I make decisions for care of my own property based on facts and logic, not angry ranting on internet forums trying to shame me into a course of action directly opposed by reality. I enjoy an informed and intelligent debate with like minded folk for the purpose of sharing information (not speculation), for a growth of knowledge. When a topic begins to go in circles and becomes antagonistic it has run it's course.

[murrays]

It's quite telling and somewhat humorous to know that you actually think the mechanisms that trap contaminants is different between air and oil filters. I've provided "facts and logic" based on actual research and physics with links to back up my position, you've provided nothing but opinion.

I suggest you do a bit of research and post the findings here if you want to posit that an air or oil filter provides peak partial removal efficiency when it is new rather than pontificate about how much better you are at arguing on the internet.

[Thumper333]

Originally Posted by murrays

It's quite telling and somewhat humorous to know that you actually think the mechanisms that trap contaminants is different between air and oil filters. I've provided "facts and logic" based on actual research and physics with links to back up my position, you've provided nothing but opinion.

I suggest you do a bit of research and post the findings here if you want to posit that an air or oil filter provides peak partial removal efficiency when it is new rather than pontificate about how much better you are at arguing on the internet.

It's more telling that you continue to twist my statements into something you can attack with insults rather than address a point head on. Clearly the MECHANISMS for filters are the same regardless of media. A filter is a porous media that traps particles from within the given source. The MECHANISMS a horse uses to walk are identical too, but I don't go to the vet when my knee acts up.

As much fun as it would be to go home and yank out my HVAC filter and strain some 50 weight through it, I think you have clearly proved you are much better at arguing on the internet. Your use of fallacies, including the classic ad hominem and pulling out your thesaurus (just the standard 'pompus' wasn't good enough to prove your perceived intellectual superiority over me, and posit? Nice one LMAO) shows you are the best internet troll alive.

Reminds me of this guy

Since I have no interest in arguing but rather was looking for a discussion (and I have no delicate ego tying my self worth to the opinion a random internet blowhard holds of me) there is nothing requiring me to further waste my time bantering with you. If someone wants to read your 'factual' link about the micron ratings and air resistance requirements of commercial duct air filters and somehow thinks that is a basis for leaving dirty oil filters in a vehicle, well that's the beauty of free will.

You can call what you have done posting facts, but the fact you can not post about and in fact have avoided responding to in anyway is that if a dirty filter is the best filter why do we buy clean ones?

I will, for fun since I am already here, drop a perfect example illustrating your point for you.

Since the ONLY performance measure of a filter is peak partial removal efficiency, this must be what you use to replace all your filters.



It'll stop everything.

[murrays]

Originally Posted by Thumper333

You can call what you have done posting facts, but the fact you can not post about and in fact have avoided responding to in anyway is that if a dirty filter is the best filter why do we buy clean ones?

As a filter (air or oil) loads up with contaminants, it a) blocks a higher percentage of contaminants (becomes more "efficient") & b) becomes more restrictive. We buy clean ones when the restriction is too high. Make sense?

Can you dispute point a)?

[Fat Panda]

Thumper & murray, I think you both are arguing about the same thing, but see it in a different point of view.

In my point of view for your arguments I see it as follows: The problem with an air filter is that air flow is restricted as the filter becomes more contaminated. The filtration rate increase as the filter becomes more contaminated, but air flow decreases. With an oil filter, the oil pump will maintain pressure no matter how clogged the oil filter becomes up to the point where it will go in to bypass, but the principal in collecting contaminants is the same.

[murrays]

Originally Posted by Hydim

Thumper & murray, I think you both are arguing about the same thing, but see it in a different point of view.

In my point of view for your arguments I see it as follows: The problem with an air filter is that air flow is restricted as the filter becomes more contaminated. The filtration rate increase as the filter becomes more contaminated, but air flow decreases. With an oil filter, the oil pump will maintain pressure no matter how clogged the oil filter becomes up to the point where it will go in to bypass, but the principal in collecting contaminants is the same.

Yep, that's it in a nutshell, pretty much what I stated in my first post on the topic. Thumper disagrees with both of us.